85
CDHF-SVU01C-EN
Reset Ratio:
The Reset Ratio is displayed as a
percentage. To use it in the above
equation it must be converted to it’s
decimal form.
Reset Ratio percent /100 = Reset
Ratio decimal
Example of converting Reset Ratio:
If the Reset Ratio displayed on the
CLD is 50 percent then use (50/100)=
.5 in the equation
TOD = Outdoor Air Temperature
Start Reset = Outdoor Air Start Reset
Example of Calculating Reset for
Outdoor Air Temperature:
If:
Reset Ratio = 35 percent
Start Reset = 80
TOD = 65
Maximum Reset = 10.5
How many Degrees of Reset will
there be?
Degrees of Reset = Reset Ratio*(Start
Reset - TOD)
Degrees of Reset = .35*(80-65)
Degrees of Reset = 5.25
(* = multiply)
If:
Reset Ratio = -70 percent
Start Reset = 90
TOD = 100
Maximum Reset = 17
How many Degrees of Reset will
there be?
Degrees of Reset = Reset Ratio* (Start
Reset - TOD)
Degrees of Reset = -7* (90-100)
Degrees of Reset = 7

Figure 32. Outdoor air temperature versus degrees of reset

Machine Protection
and Adaptive
Control